JP7375604B2 - Engine exhaust circulation system - Google Patents

Description

The present invention relates to an exhaust gas circulation system for an engine, which includes, for example, an exhaust pipe curved away from the engine and an EGR system that recirculates a portion of exhaust gas to an intake system.

2. Description of the Related Art Vehicles such as automobiles are known to be equipped with an exhaust gas circulation device that discharges exhaust gas emitted by an engine to the outside and returns a portion of the exhaust gas to an intake device.

For example, Patent Document 1 describes an exhaust purification device that purifies exhaust gas emitted by an engine, an exhaust pipe that guides the exhaust gas that has passed through the exhaust purification device to the outside, and a part of the exhaust gas that is returned to the intake device. An exhaust gas recirculation system is disclosed that includes an exhaust gas recirculation (hereinafter referred to as "EGR") system.

Incidentally, in recent years, in vehicles such as automobiles, the floor of the cabin has been lowered to improve the comfort inside the cabin, or space for placing the battery for driving has been secured on the lower side of the cabin floor. There's something I'm doing. In this case, for example, in a vehicle with a vertical engine, the exhaust pipe cannot be installed in a substantially straight line toward the rear of the vehicle, so immediately after the exhaust purification device, the exhaust pipe should be installed across the vehicle width so that it is spaced apart from the engine. It must be curved outward.

Furthermore, in a vehicle equipped with an EGR device as in Patent Document 1, it is necessary to secure a space for arranging the EGR device in the vertical direction, so there is a problem that the size of the exhaust circulation device tends to increase. Ta. In particular, in vehicles with vertical engines, dead space tends to occur outside the curved portion of the exhaust pipe in the vehicle width direction, so there is room for improvement.

JP2019-127920A

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide an exhaust gas circulation system for an engine that can prevent the size of the exhaust pipe from increasing even when the exhaust pipe is curved away from the engine. do.

The present invention provides an exhaust purification device for purifying exhaust gas discharged by an engine mounted in an engine room of a vehicle, an exhaust pipe for guiding the exhaust gas that has passed through the exhaust purification device to the outside, and the exhaust purification device. An exhaust gas circulation device for an engine, comprising an EGR device that recirculates a portion of the exhaust gas that has passed through the engine to an intake device, the exhaust pipe having an upstream portion extending in the longitudinal direction of the vehicle, and an upstream portion spaced apart from the engine. , a curved portion having a downstream portion extending outward in the vehicle width direction from a rear end of the upstream portion, the EGR device includes an EGR cooler that cools the exhaust gas, and the EGR cooler is disposed outside in the vehicle width direction of the upstream portion of the curved portion, and further forward of the vehicle than the downstream portion of the curved portion, and is positioned so as to overlap the upstream portion of the curved portion when viewed from the vehicle width direction ; The upstream portion of the curved portion has an inclined surface that intersects with the vehicle width direction so that the upper end is located inside the vehicle width direction with respect to the lower end. The EGR cooler is provided on the outside in the vehicle width direction, and is disposed facing the inclined surface of the curved portion and tilted along the inclined surface.

The present invention also provides an exhaust purification device for purifying exhaust gas emitted by an engine mounted in an engine room of a vehicle, an exhaust pipe for guiding the exhaust gas that has passed through the exhaust purification device to the outside, and the exhaust purification device. An exhaust gas circulation system for an engine, comprising: an EGR system that recirculates a part of the exhaust gas that has passed through the exhaust pipe to an intake system, the exhaust pipe having an upstream part extending in the longitudinal direction of the vehicle and a part separated from the engine. and a downstream portion extending outward in the vehicle width direction from the rear end of the upstream portion, the EGR device includes an EGR cooler that cools the exhaust gas, and the EGR cooler The curved portion of the exhaust pipe is disposed further forward of the vehicle than the downstream portion of the exhaust pipe and overlaps the upstream portion of the curved portion when viewed from the vehicle width direction. The EGR cooler is provided with an inclined surface on the outside in the vehicle width direction that is inclined so as to intersect with each other. It is characterized by being connected along the vehicle width direction.

According to this invention, the EGR device can be disposed by effectively utilizing the dead space generated on the vehicle front side of the downstream portion of the curved portion and on the outside of the upstream portion in the vehicle width direction. Therefore, even if the exhaust pipe and the EGR device are arranged side by side in the vehicle width direction, the engine exhaust gas circulation device can be prevented from increasing in size in the vehicle width direction.

Furthermore, compared to, for example, a case where the EGR device is connected to the exhaust pipe so as to extend in the vertical direction, the exhaust gas circulation device of the engine can reduce the length of the EGR device in the vertical direction. Therefore, the engine exhaust gas circulation device can be prevented from increasing in size not only in the vehicle width direction but also in the vertical direction.

Therefore, even if an engine exhaust circulation system is equipped with an exhaust pipe that is curved away from the engine, the dead space created on the outside of the curved part in the vehicle width direction can be effectively used to reduce the size of the exhaust pipe. It is possible to suppress the increase in size.

Furthermore, in the present invention , the EGR device includes an EGR cooler that cools the exhaust gas, and the curved portion of the exhaust pipe has an inclined surface that is inclined to cross the vehicle width direction toward the outside in the vehicle width direction. The EGR cooler is arranged in a tilted state along the inclined surface of the curved portion.
According to this configuration, in the engine exhaust circulation device, the EGR cooler with a reduced vertical height can be arranged in parallel to the curved portion of the exhaust pipe.

Therefore, the exhaust gas circulation system for the engine can suppress the size of the EGR system in the vertical direction.
Therefore, even if the exhaust gas circulation device for the engine is provided with an exhaust pipe that is curved away from the engine, it is possible to further suppress the size of the exhaust gas circulation device from increasing.

Further, in the present invention , the EGR cooler is connected to the curved portion of the exhaust pipe along the vehicle width direction.
According to this configuration, the exhaust gas circulation device of the engine can be prevented from increasing in size, and can also prevent problems caused by the load applied via the EGR cooler.

Specifically, for example, when an almost upright EGR cooler is connected vertically to the exhaust pipe, the entire weight of the EGR device is likely to act on the exhaust pipe, causing flexural deformation of the exhaust pipe. There is a risk that unintended problems may occur.

On the other hand, since the tilted EGR cooler is connected along the vehicle width direction, the engine exhaust circulation system acts on the connection point between the curved part of the exhaust pipe and the EGR device via the EGR cooler. The load can be reduced. Therefore, the engine exhaust circulation device can suppress the bending deformation of the exhaust pipe and easily ensure the strength of the connection point between the curved portion of the exhaust pipe and the EGR device.

Therefore, the engine exhaust gas circulation device can be prevented from increasing in size, and problems caused by the load applied via the EGR cooler can be prevented.

Further, as an aspect of the present invention, the EGR device includes a plurality of EGR valves that adjust the flow rate of the exhaust gas above the EGR cooler, and the plurality of EGR valves are wider than the EGR cooler. It may be arranged on the inside in the direction.

According to this configuration, the engine exhaust circulation device transfers the load acting on the connection point between the curved part of the exhaust pipe and the EGR device via the EGR cooler to the lower end of the EGR cooler and the plurality of EGR valves, which are connected to the vehicle width. This can be reduced compared to the case where they are located at approximately the same position in the direction.
Therefore, even when a plurality of EGR valves are provided in the engine exhaust gas circulation system, it is possible to reliably prevent problems caused by the load applied via the EGR cooler.

Further, as an aspect of the present invention, a portion of the EGR device above the EGR cooler may be fastened and fixed to the engine via a bracket.
According to this configuration, the engine exhaust gas circulation device can support the EGR device both on the curved portion of the exhaust pipe and on the engine.

Therefore, the engine exhaust circulation device can more reliably reduce the load acting on the connection point between the curved portion of the exhaust pipe and the EGR device via the EGR cooler.
Therefore, the engine exhaust gas circulation system can more reliably prevent problems caused by the load applied via the EGR cooler.

According to the present invention, it is possible to provide an exhaust gas circulation device for an engine that can prevent the size of the exhaust pipe from increasing even when the exhaust pipe is curved away from the engine.

FIG. 1 is a schematic diagram showing an outline of the configuration of a vehicle. FIG. 3 is a side view showing the external appearance of the exhaust circulation device as seen from the right side in the vehicle width direction. A cross-sectional view taken along the line AA in FIG. 2. FIG. 3 is a rear view showing the external appearance of the exhaust circulation device as seen from the rear. FIG. 3 is a side view showing the external appearance of the exhaust circulation device as seen from the left side in the vehicle width direction. FIG. 3 is an external perspective view showing the external appearance of the connection point between the first exhaust pipe and the EGR cooler as seen from below the vehicle. FIG. 2 is an external perspective view showing the external appearance of the EGR device. FIG. 3 is a rear view showing the appearance of the bracket.

An embodiment of this invention will be described below with reference to the drawings.
In this embodiment, in a vehicle equipped with a diesel engine (hereinafter referred to as the "engine") that uses light oil as fuel, the exhaust gas emitted by the engine is led out of the vehicle, and a portion of the exhaust gas is transferred to the intake air. The exhaust gas circulation device that recirculates the exhaust gas to the device will be explained using FIGS. 1 to 8.

Note that FIG. 1 shows a schematic diagram of the configuration of the vehicle 1, FIG. 2 shows a side view of the exhaust circulation system 10 seen from the right side in the vehicle width direction, and FIG. 3 shows a cross-sectional view taken along the line AA in FIG. FIG. 4 shows a rear view of the exhaust circulation device 10.

Furthermore, FIG. 5 shows a side view of the exhaust circulation system 10 as seen from the left side in the vehicle width direction, and FIG. 6 shows an external perspective view of the connection point between the first exhaust pipe 14 and the EGR cooler 181 as seen from the bottom of the vehicle. 7 shows an external perspective view of the EGR device 17, and FIG. 8 shows a rear view of the bracket 20.

Further, in FIG. 1, arrow Fr and arrow Rr indicate the front-rear direction, with arrow Fr indicating the front and arrow Rr indicating the rear. Furthermore, the arrow Rh and the arrow Lh indicate the vehicle width direction, the arrow Rh indicates the right direction, and the arrow Lh indicates the left direction.

First, as shown in FIG. 1, the vehicle 1 includes an engine 2 arranged vertically, a transmission 3 connected to the rear of the engine 2, an intake device 4 connected to the left side of the engine 2, and an engine 2. An exhaust circulation system 10 connected to the right side of the vehicle 2 is provided at the front of the vehicle.

As shown in FIG. 1, the intake device 4 takes in outside air via an air cleaner 41 and introduces it into the engine 2 as fresh air. As shown in FIG. 2, this intake device 4 includes an air duct 42 that communicates an air cleaner 41 with the engine 2. It is connected to 2.

Although the details will be described later, the exhaust circulation device 10 includes an exhaust manifold 11, a first catalyst 12, a second catalyst 13, a first exhaust pipe 14, a second exhaust pipe 15, and a silencer, as shown in FIG. 16 are connected in this order from the engine 2 toward the rear of the vehicle.

As shown in FIG. 1, the exhaust circulation device 10 has a first exhaust pipe 14 disposed at the front of the vehicle, a second exhaust pipe 15 disposed at the passenger compartment, and a silencer 16 disposed at the rear of the vehicle. There is.
As shown in FIG. 1, such a vehicle 1 has a low floor portion 1a formed behind the engine 2 and transmission 3 in order to secure space within the vehicle interior.

Therefore, as shown in FIG. 1, the first exhaust pipe 14 of the exhaust circulation device 10 extends outward in the vehicle width direction from the second catalyst 13 so as to be spaced apart from the engine 2 in the vehicle width direction. It is bent into a crank shape.

Furthermore, as shown in FIG. 1, the second exhaust pipe 15 of the exhaust circulation device 10 is formed in a shape extending along the vehicle longitudinal direction on the inside of the side sill (not shown) in the vehicle width direction. In other words, the second exhaust pipe 15 is formed adjacent to the outer side of the low floor portion 1a in the vehicle width direction, and has a shape extending in the vehicle longitudinal direction.

Next, the above-described exhaust gas circulation system 10 for the vehicle 1 will be described in further detail using FIGS. 2 to 8.
As shown in FIGS. 1 and 2, the exhaust circulation system 10 includes an exhaust manifold 11 connected to the right side of the engine 2, a first catalyst 12 connected to the exhaust manifold 11 via a turbocharger 5, It is composed of a second catalyst 13, a first exhaust pipe 14, a second exhaust pipe 15, a silencer 16, and an EGR device 17 that recirculates a portion of exhaust gas to the intake device 4.

The first catalyst 12 and the second catalyst 13 are exhaust purification devices that purify exhaust gas discharged by the engine 2.
As shown in FIG. 2, the first catalyst 12 is, for example, an oxidation catalyst, and is connected to the exhaust manifold 11 via a turbocharger 5 whose detailed illustration is omitted.

The first catalyst 12 is formed so as to cause the exhaust gas to flow down from the rear of the vehicle toward the front of the vehicle, and then flow down toward the bottom of the vehicle.
Specifically, as shown in FIG. 2, the first catalyst 12 includes a substantially cylindrical body portion extending from the turbocharger 5 toward the front of the vehicle, and a substantially cylindrical body portion extending from the front end of the generally cylindrical body portion toward the vehicle bottom. It consists of an open exit part.

As shown in FIG. 2, the second catalyst 13 is, for example, a diesel particulate removal filter, and is connected to the outlet portion of the first catalyst 12. This second catalyst 13 is formed in a shape that causes the exhaust gas that has passed through the first catalyst 12 to flow down from the front of the vehicle toward the rear of the vehicle.
Specifically, as shown in FIGS. 2 and 3, the second catalyst 13 is formed into a substantially cylindrical body having a substantially elongated oval shape extending in the longitudinal direction of the vehicle.

Moreover, the first exhaust pipe 14 is formed in a shape that causes the exhaust gas that has passed through the second catalyst 13 to flow down toward the right side in the vehicle width direction and then flow down toward the rear and downward direction of the vehicle.
Specifically, as shown in FIG. 4, the first exhaust pipe 14 includes a curved part 141 connected to the lower part of the second catalyst 13, and a straight part 142 extending from the curved part 141 toward the rear of the vehicle and downward. , is formed into a substantially cylindrical body that is substantially crank-shaped in plan view.

As shown in FIG. 4, the curved portion 141 of the first exhaust pipe 14 is directed from the lower part of the second catalyst 13 toward the right side in the vehicle width direction and toward the bottom of the vehicle so as to be separated from the engine 2 toward the right side in the vehicle width direction. It is formed into a substantially curved cylindrical shape.

More specifically, as shown in FIGS. 4 and 5, the curved portion 141 includes an upstream portion 141a that extends from the lower part of the second catalyst 13 toward the rear of the vehicle and downward, and a rear end of the upstream portion 141a that extends from the rear end of the upstream portion 141a to the right side in the vehicle width direction and below the vehicle. and a downstream portion 141b extending toward.
As shown in FIG. 3, the curved portion 141 has a substantially trapezoidal cross-sectional shape in a longitudinal section along the vehicle width direction, with a short side at the upper end and an oblique side on the right side in the vehicle width direction. ing.

Therefore, as shown in FIG. 3, the upstream portion 141a of the curved portion 141 has an upper end located on the left side in the vehicle width direction with respect to a lower end in a longitudinal section along the vehicle width direction. An inclined surface 141c that intersects with the other is formed.
On the other hand, as shown in FIGS. 2 and 4, the straight portion 142 of the first exhaust pipe 14 is formed into a substantially cylindrical shape that extends substantially linearly from the downstream portion 141b of the curved portion 141 toward the rear and downward direction of the vehicle. .

Further, as shown in FIG. 1, the second exhaust pipe 15 is formed in a shape that causes the exhaust gas that has passed through the first exhaust pipe 14 to flow down from the front of the vehicle toward the rear of the vehicle.
Further, as shown in FIG. 1, the silencer 16 is configured to reduce exhaust noise and discharge the exhaust gas that has passed through the second exhaust pipe 15 to the outside.

Further, the EGR device 17 is a device that guides a portion of the exhaust gas that has flowed into the first exhaust pipe 14 from below the vehicle toward the top of the vehicle, and also circulates it back to the intake device 4 . As shown in FIGS. 2 and 5, the EGR device 17 includes a first EGR passage 18 and a second EGR passage 19 that communicate the first exhaust pipe 14 and the intake device 4.

As shown in FIGS. 2 and 5, the first EGR passage 18 includes an EGR cooler 181 that cools the introduced exhaust gas, a first EGR valve 182 that adjusts the flow rate of the exhaust gas, and a first EGR valve 182 that connects the first EGR valve 182 to the intake device 4. It is composed of a first inner pipe 183 and a first outer pipe 184 that communicate with each other.

More specifically, as shown in FIGS. 2 and 4, the EGR cooler 181 has a generally hollow box shape that is long in the vertical direction of the vehicle, and is configured to allow exhaust gas to flow downward from the bottom of the vehicle to the top of the vehicle. ing.

Note that a water-cooled heat exchanger 181a, whose detailed illustration is omitted, is installed inside the EGR cooler 181 (see FIG. 3).
As shown in FIGS. 3 and 6, the EGR cooler 181 is disposed close to the upstream portion 141a of the curved portion 141 of the first exhaust pipe 14.

Specifically, as shown in FIGS. 3 to 5, the EGR cooler 181 is disposed on the vehicle front side relative to the downstream portion 141b of the curved portion 141, and is disposed on the upstream side of the curved portion 141 when viewed from the right side in the vehicle width direction. It is arranged so as to overlap the portion 141a.

As shown in FIG. 3, the lower end of this EGR cooler 181 is fastened and fixed along the vehicle width direction so as to communicate with the lower part of the upstream portion 141a of the curved portion 141 in the vehicle width direction.
Furthermore, as shown in FIG. 3, the EGR cooler 181 is arranged in a state in which a side surface 181b on the left side in the vehicle width direction is inclined along an inclined surface 141c of the curved portion 141 in a longitudinal section along the vehicle width direction. has been done.

As shown in FIGS. 2 and 7, the upper end of the EGR cooler 181 is connected from the right side in the vehicle width direction to the first EGR valve 182 located above the vehicle in the upstream portion 141a of the curved portion 141 when viewed from the rear. has been done.
As shown in FIG. 4, the EGR cooler 181 is thus disposed so as to fit into the dead space created on the right side of the first exhaust pipe 14 in the vehicle width direction by the curved portion 141.

Further, as shown in FIGS. 2 and 4, the first EGR valve 182 is located on the left side in the vehicle width direction with respect to the upper end of the EGR cooler 181 and located above the vehicle in the upstream portion 141a of the curved portion 141 of the first exhaust pipe 14. placed in position.

The first EGR valve 182 is connected to the upper end of an EGR cooler 181 on the right side in the vehicle width direction so as to communicate in the vehicle width direction, and the lower end of the first inner pipe 183 on the left side in the vehicle width direction is connected to the first EGR valve 182 so as to communicate in the vehicle width direction. is connected to.

Further, the first inner pipe 183 and the first outer pipe 184 communicate with each other, and also allow the first EGR valve 182 and the intake device 4 to communicate with each other, as shown in FIGS. 2, 5, and 7.
Note that, as shown in FIG. 4, the first inner pipe 183 and the first outer pipe 184 are arranged in approximately the same range in the vehicle width direction as the range in the vehicle width direction of the first exhaust pipe 14 when viewed from the rear. ing.

Specifically, as shown in FIG. 4, the first inner pipe 183 is arranged on the left side in the vehicle width direction with respect to the first EGR valve 182 when viewed from the rear. Furthermore, as shown in FIG. 5, the first inner pipe 183 extends upward from the first EGR valve 182 when viewed from the left side in the vehicle width direction, and then bends toward the front of the vehicle, forming a substantially L-shape in side view. It is formed.

As shown in FIG. 7, the upper end of the first inner pipe 183 is connected to the first outer pipe 184 on the vehicle front side of a second EGR valve 192, which will be described later.
On the other hand, as shown in FIG. 4, the first outer pipe 184 is arranged on the right side in the vehicle width direction with respect to the first EGR valve 182 when viewed from the rear.

As shown in FIGS. 2, 4, and 7, the first outer pipe 184 extends from the lower end connected to the upper end of the first inner pipe 183 to the right side in the vehicle width direction, and then curves upward to the rear of the vehicle. It is formed into a U-shape when viewed.
The upper end of the first outer pipe 184 is connected to an air duct 42 that connects the air cleaner 41 and the turbocharger 5, as shown in FIGS. 2 and 7.

Further, as shown in FIGS. 2, 3, and 7, the second EGR passage 19 includes a second outer pipe 191 connected to the first exhaust pipe 14, and a second EGR valve 192 that adjusts the flow rate of exhaust gas. The first EGR passage 18 communicates with the intake device 4 via the first EGR passage 18.

As shown in FIG. 4, the second outer pipe 191 is arranged on the right side in the vehicle width direction with respect to the first EGR valve 182 when viewed from the rear. Note that, as shown in FIG. 4, the second outer pipe 191 is arranged to be located between the inclined surface 141c of the first exhaust pipe 14 and the right end of the first outer pipe 184 in the vehicle width direction. ing.

More specifically, as shown in FIG. 3, the lower end of the second outer pipe 191 is connected to the upper part of the upstream portion 141a of the curved portion 141 of the first exhaust pipe 14 in the vehicle width direction. It is fastened and fixed along the direction.
Further, as shown in FIGS. 2 and 7, the second outer pipe 191 extends from the first exhaust pipe 14 toward the rear of the vehicle, and then curves upward in a side view, when viewed from the right side in the vehicle width direction. It is formed in the shape of

Further, as shown in FIGS. 2 and 4, the second EGR valve 192 is located at approximately the same position in the longitudinal direction of the vehicle as the first EGR valve 182 and at approximately the same position in the vehicle width direction as the first EGR valve 182. is located close to the top of the vehicle.

The second EGR valve 192 is connected to the upper end of a second outer pipe 191 on the right side in the vehicle width direction so as to communicate in the vehicle width direction.
Furthermore, as shown in FIGS. 5 and 7, the second EGR valve 192 is connected to the first inner pipe 183 of the first EGR passage 18, and is connected to the intake device 4 via the first outer pipe 184 of the first EGR passage 18. It's communicating.

In this way, the EGR device 17 is configured to allow a portion of the exhaust gas that has passed through the second catalyst 13 to flow from below the vehicle toward the top of the vehicle and to be introduced into the intake device 4 .
As shown in FIG. 8, the EGR device 17 configured as described above connects the first inner pipe 183 of the first EGR passage 18 located downstream of the EGR cooler 181 in the exhaust gas flow direction via the bracket 20. It is supported by being fastened and fixed to the engine 2.
Specifically, as shown in FIG. 8, the bracket 20 is formed of a substantially plate-shaped body having a thickness in the vehicle width direction.

As shown in FIGS. 5 and 8, this bracket 20 has its upper portion fastened and fixed to the first EGR valve 182 via a flange portion 183a of the first inner pipe 183 in the first EGR passage 18. In other words, the upper part of the bracket 20 is jointly fastened to a fastening location between the first inner pipe 183 of the first EGR passage 18 and the first EGR valve 182.

Further, as shown in FIG. 8, the lower part of the bracket 20 is fastened and fixed to a boss portion 2a that projects from the right side of the engine 2 to the right side in the vehicle width direction.
In this way, the EGR device 17 has the first EGR passage 18 and the second EGR passage 19 disposed within the range of the first exhaust pipe 14 in the vehicle width direction so as to extend in the vehicle vertical direction. The dead space created on the right side of the first exhaust pipe 14 in the vehicle width direction is effectively utilized.

As described above, the exhaust gas circulation device 10 for the engine 2 includes an exhaust purification device (first catalyst 12, second catalyst 13) that purifies exhaust gas emitted by the engine 2 mounted in the engine room of the vehicle 1, and an exhaust gas circulation device 10 for the engine 2. A first exhaust pipe 14 that guides the exhaust gas that has passed through the purification device (first catalyst 12, second catalyst 13) to the outside, and a first exhaust pipe 14 that guides the exhaust gas that has passed through the exhaust purification device (first catalyst 12, second catalyst 13) to the outside. An EGR device 17 that partially recirculates a portion of the air to the intake device 4 is provided.

This first exhaust pipe 14 has a curved portion 141 having an upstream portion 141a extending in the longitudinal direction of the vehicle, and a downstream portion 141b extending toward the right side in the vehicle width direction from the rear end of the upstream portion 141a so as to be separated from the engine 2. It is equipped with the following.
Further, the EGR device 17 is disposed further forward of the vehicle than the downstream portion 141b of the curved portion 141, and the EGR cooler 181 is disposed so as to overlap the upstream portion 141a of the curved portion 141 when viewed from the right side in the vehicle width direction. It is something.

According to this invention, the exhaust gas circulation system 10 of the engine 2 effectively utilizes the dead space generated on the front side of the vehicle than the downstream portion 141b of the curved portion 141 and on the right side of the upstream portion 141a in the vehicle width direction. 17 can be placed. Therefore, even if the first exhaust pipe 14 and the EGR device 17 are arranged side by side in the vehicle width direction, the exhaust gas circulation device 10 of the engine 2 can be prevented from increasing in size in the vehicle width direction.

Furthermore, compared to, for example, a case where the EGR device is connected to the first exhaust pipe so as to extend in the vertical direction of the vehicle, the exhaust gas circulation device 10 of the engine 2 can suppress the length of the EGR device 17 in the vertical direction of the vehicle. I can do it. Therefore, the exhaust gas circulation system 10 of the engine 2 can be prevented from increasing in size not only in the vehicle width direction but also in the vehicle vertical direction.

Therefore, even when the exhaust gas circulation system 10 for the engine 2 is provided with the first exhaust pipe 14 that is curved away from the engine 2, it is possible to effectively utilize the dead space generated on the right side of the curved portion 141 in the vehicle width direction. By doing so, it is possible to suppress the increase in size.

Further, the EGR device 17 includes an EGR cooler 181 that cools exhaust gas. Further, the curved portion 141 of the first exhaust pipe 14 includes an inclined surface 141c on the right side in the vehicle width direction, which is inclined to intersect with the vehicle width direction. The EGR cooler 181 is arranged in a tilted state along the inclined surface 141c of the curved portion 141.

According to this configuration, the exhaust circulation system 10 for the engine 2 can arrange the EGR cooler 181 in a state where the height in the vertical direction of the vehicle is suppressed in parallel to the curved portion 141 of the first exhaust pipe 14.

Therefore, the exhaust gas circulation device 10 of the engine 2 can suppress the size of the EGR device 17 in the vertical direction of the vehicle.
Therefore, even when the exhaust gas circulation device 10 for the engine 2 is provided with the first exhaust pipe 14 that is curved away from the engine 2, it is possible to further prevent the exhaust gas circulation device 10 from increasing in size.

Further, the EGR cooler 181 is connected to the curved portion 141 of the first exhaust pipe 14 along the vehicle width direction.
According to this configuration, the exhaust gas circulation device 10 of the engine 2 can suppress an increase in size and can prevent problems caused by a load applied via the EGR cooler 181.

Specifically, for example, when a substantially upright EGR cooler is connected to the first exhaust pipe along the vertical direction of the vehicle, the entire weight of the EGR device is likely to act on the first exhaust pipe. 1. Unintended problems such as bending and deformation of the exhaust pipe may occur.

On the other hand, since the EGR cooler 181 in the tilted state is connected along the vehicle width direction, the exhaust circulation device 10 of the engine 2 connects to the curved portion 141 of the first exhaust pipe 14 via the EGR cooler 181. The load acting on the connection point with the EGR device 17 can be reduced. Therefore, the exhaust circulation device 10 of the engine 2 can suppress the bending deformation of the first exhaust pipe 14 and easily ensure the strength of the connection point between the curved portion 141 of the first exhaust pipe 14 and the EGR device 17. can.

Therefore, the exhaust gas circulation device 10 of the engine 2 can suppress its size from increasing and can prevent problems caused by the load applied via the EGR cooler 181.

Further, the EGR device 17 includes a first EGR valve 182 and a second EGR valve 192 that adjust the flow rate of exhaust gas above the EGR cooler 181 in the vehicle.
The first EGR valve 182 and the second EGR valve 192 are arranged on the left side of the EGR cooler 181 in the vehicle width direction.

According to this configuration, the exhaust circulation device 10 of the engine 2 transfers the load acting on the connection point between the curved portion 141 of the first exhaust pipe 14 and the EGR device 17 via the EGR cooler 181 to the lower end of the EGR cooler, This can be reduced compared to the case where the first EGR valve and the second EGR valve are located at substantially the same position in the vehicle width direction.
Therefore, even when the exhaust circulation system 10 of the engine 2 is provided with the first EGR valve 182 and the second EGR valve 192, it is possible to reliably prevent problems caused by the load applied via the EGR cooler 181.

Further, in the EGR device 17, a first inner pipe 183 located above the EGR cooler 181 in the vehicle is fastened and fixed to the engine 2 via a bracket 20.
According to this configuration, the exhaust gas circulation device 10 for the engine 2 can support the EGR device 17 by both the curved portion 141 of the first exhaust pipe 14 and the engine 2.

Therefore, the exhaust circulation device 10 of the engine 2 can more reliably reduce the load acting on the connection point between the curved portion 141 of the first exhaust pipe 14 and the EGR device 17 via the EGR cooler 181.
Therefore, the exhaust gas circulation system 10 of the engine 2 can more reliably prevent problems caused by the load applied via the EGR cooler 181.

In the correspondence between the configuration of this invention and the above-described embodiments,
The exhaust purification device of the present invention corresponds to the first catalyst 12 and the second catalyst 13 of the embodiment,
Similarly below,
The exhaust pipe corresponds to the first exhaust pipe 14,
The outside in the vehicle width direction corresponds to the right side in the vehicle width direction,
The plurality of EGR valves correspond to a first EGR valve 182 and a second EGR valve 192,
The inside in the vehicle width direction corresponds to the left side in the vehicle width direction,
The part above the EGR cooler corresponds to the first inner pipe 183,
This invention is not limited to the configuration of the above-described embodiments, and can be implemented in many other embodiments.

For example, in the embodiment described above, the vehicle 1 has the engine 2 that uses light oil as fuel and is vertically disposed at the front of the vehicle, but the present invention is not limited to this, and an engine that uses gasoline as fuel may be used.
Furthermore, the vehicle may have a horizontal engine placed at the front of the vehicle.

In addition, although the vehicle 1 is equipped with the low floor portion 1a at the rear of the engine 2, the present invention is not limited to this, and the vehicle is equipped with a battery that is disposed so as to cover the entire surface of the cabin floor from the bottom of the vehicle. There may be.
Further, although the configuration includes the turbocharger 5 communicating with the engine 2, the present invention is not limited to this, and a configuration without the turbocharger may be used.

Further, although the exhaust purification device is configured with the first catalyst 12 and the second catalyst 13, the present invention is not limited to this, and any exhaust gas purification device configured with one catalyst can be used as long as the configuration can purify exhaust gas. There may be.
Further, although the EGR device 17 is configured to include the first EGR passage 18 and the second EGR passage 19, the EGR device 17 is not limited to this, and may be an EGR device configured only by the first EGR passage.

Further, in the first EGR passage 18, the first EGR valve 182 and the intake device 4 are communicated via the first inner pipe 183 and the first outer pipe 184, but the first EGR valve 182 and the intake device 4 are communicated with each other. The first EGR valve 182 and the intake device 4 may be communicated through a pipe integrally formed with the first outer pipe.

Furthermore, in the second EGR passage 19 , the second EGR valve 192 and the intake device 4 are communicated via the first outer pipe 184 of the first EGR passage 18 , but the present invention is not limited to this. The second EGR valve 192 and the intake device 4 may be communicated via a pipe provided separately from the outer pipe 184.

Further, although the first inner pipe 183 of the EGR device 17 is fastened and fixed to the engine 2 via the bracket 20, the structure is not limited to this, and the portion above the EGR cooler 181 is Any suitable configuration may be used as long as it is fastened and fixed to the engine.
For example, the second EGR valve 192 located above the first EGR valve 182 in the vehicle may be fastened and fixed to the engine 2 via a bracket.

2... Engine 4... Intake device 10... Exhaust circulation device 12... First catalyst 13... Second catalyst 14... First exhaust pipe 17... EGR device 20... Bracket 141... Curved portion 141a... Upstream portion 141b... Downstream portion 141c... Inclined Surface 181...EGR cooler 182...First EGR valve 183...First inner pipe 192...Second EGR valve

Claims (5)

An exhaust purification device that purifies exhaust gas emitted by an engine installed in the engine room of a vehicle;
an exhaust pipe that guides the exhaust gas that has passed through the exhaust purification device to the outside;
An exhaust gas circulation device for an engine, comprising an EGR device that recirculates a part of the exhaust gas that has passed through the exhaust purification device to an intake device,
The exhaust pipe is
a curved portion having an upstream portion extending in the longitudinal direction of the vehicle, and a downstream portion extending outward in the vehicle width direction from the rear end of the upstream portion so as to be spaced from the engine;
The EGR device includes:
comprising an EGR cooler that cools the exhaust gas,
The EGR cooler is
Arranged outside in the vehicle width direction of the upstream portion of the curved portion and further forward of the vehicle than the downstream portion of the curved portion, and arranged so as to overlap the upstream portion of the curved portion when viewed from the vehicle width direction. is ,
The direction opposite to the outside in the vehicle width direction is the inside in the vehicle width direction,
The upstream portion of the curved portion is
A sloped surface that intersects with the vehicle width direction is provided on the outside in the vehicle width direction so that the upper end is located on the inside in the vehicle width direction with respect to the lower end,
The EGR cooler is
The curved portion is arranged opposite to the inclined surface and tilted along the inclined surface.
Engine exhaust circulation system. The EGR cooler is
connected along the vehicle width direction to the curved part of the exhaust pipe
An exhaust gas circulation device for an engine according to claim 1 . An exhaust purification device that purifies exhaust gas emitted by an engine installed in the engine room of a vehicle;
an exhaust pipe that guides the exhaust gas that has passed through the exhaust purification device to the outside;
An exhaust gas circulation device for an engine, comprising an EGR device that recirculates a part of the exhaust gas that has passed through the exhaust purification device to an intake device,
The exhaust pipe is
a curved portion having an upstream portion extending in the longitudinal direction of the vehicle, and a downstream portion extending outward in the vehicle width direction from the rear end of the upstream portion so as to be spaced from the engine;
The EGR device includes:
comprising an EGR cooler that cools the exhaust gas,
The EGR cooler is
disposed further forward of the vehicle than the downstream portion of the curved portion, and positioned so as to overlap the upstream portion of the curved portion when viewed from the vehicle width direction;
The curved portion of the exhaust pipe is
A sloped surface that is inclined to cross the vehicle width direction is provided on the outside in the vehicle width direction,
The EGR cooler is
The exhaust pipe is arranged in a tilted state along the inclined surface of the curved portion, and is connected to the curved portion of the exhaust pipe along the vehicle width direction.
Engine exhaust circulation system. The EGR device includes:
A plurality of EGR valves are provided above the EGR cooler to adjust the flow rate of the exhaust gas,
The plurality of EGR valves are
It is located inside the EGR cooler in the vehicle width direction.
An exhaust gas circulation system for an engine according to claim 2 or 3 . The EGR device includes:
A portion above the EGR cooler was fastened and fixed to the engine via a bracket.
The exhaust gas circulation device for an engine according to any one of claims 2 to 4 .

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